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پیاپی 2 (پاییز و زمستان 1392)

Verticillium disease is one of the most important cotton diseases which led to limitations in cultivation and yeild reduction. The study was used fungal toxin Verticillium as selection agent of cotton callus cells resistant. The explants were prepared from sterilized 7-days old cotton seedling and were cultured on MS medium with 2 mg/l of each growth regulators NAA and BAP in order to produce callus. Following the initial weighing , the resulting callus were transferred to the new media mid 0.5 mg/l of NAA and BAP concentrations with zero (control ), 5, 10, 20, and 30 percent pathogen toxins, and after 3 weeks their relative growth was calculated. The highest relative callus growth was in non-toxin medium and the lowest one was in pathogen toxin concentrations of 20 and 30 percent. Golestan made more relative callus growth rate in non-toxin medium and the 5 percent toxin concentration, respectively, with 115.2, and 100 percent. Toxin concentrations of 20 and 30 percent showed the lowest relative growth rate of callus with 24.5 and 8 percent, respectively in Sahel cultivar. Golestan, Coker-100 wilt and Sahel calli that were green-white colored, didn’t change in 5 and 10 percent of toxin concentrations but discolored to brown with concentration increasing. Callus of Hashemabad Native cultivar that was cream, discolored to brown in the range of toxins from 5 to 30 percent. In general, this color change indicates the effect of the toxin on the quality of calli. So this method can be accelerate the screening of tolerance plant with selection of suitable calli.

Knowledge of management factors effect on plants and consumption the maximum capacity of environment can increase crop yield. Application of crops growth simulation models is a valuable approach to identify the impact of various management factors on yield. If the necessary information of each crop in each region is accessed, it is possible to use crop growth models. The aim of this study was to evaluate effect of planting density (250000 and 62500 plants per hectare) and cotton varieties (Golestan, Sepid and Armaghan) on extinction coefficient and radiation use efficiency. The experiment was carried out as split plot design based on randomized complete block design whit three replications in 2011. The plant density was as main plot factor while cotton varieties were considered as sub-plot factor. The results showed that effect of variety on the extinction coefficient and radiation use efficiency was not significant. Extinction coefficient decreased significantly from 0.87 to 0.61 when plant density was increased. However, the radiation use efficiency was 1.35 and 3.17 g.MJ-1 respectively for 62500 and 250,000 plants per hectare density. Higher plant density increased leaf area index and canopy closure at higher temperatures which caused to increase the radiation use efficiency in 250,000 plants density.

The cotton is unique plant in terms importance of food, medicine and industrial uses. Because of the considerable exchange technology and property income, employment and relative advantage of cotton, it is considered as a strategic and important crop to the national economy. During past two decades, trade and pricing policies on production, cultivated area and export of cotton has been more effective than any other regional crops. This study was carried out to determine the effects of removing energy subsidies policy on costs of cotton and its production, contribution of agricultural inputs costs and energy carriers and final price of the cotton in Golestan province. During a time-scaled, data was collected from production cost database of agricultural products and 20 questionnaires completed by scholars and experts using the Delphi approach. The costs of production, agricultural inputs, and final price of cotton were calculated by using modified industrial cost accounting techniques into three adjusting subsidies scenario "before policy accomplishment" (, price of gasoline and electricity in 165 and 20 Rials, respectively), "during the policy accomplishment "(the current situation with the price of gasoline in 1500, 3500 and electricity in 140 Rials) and" after policy implementation "(final price of energy carriers, the price of gasoline and electricity in 550 7900 Rials, respectively. The results showed that the cost of cotton production was increased during (1&2) and after implementation of the policy as 5, 12 and 23 percent, respectively, due to increasing gasoline. In terms increasing electricity price, cotton production was increased during and after implementation of the policy as 42 and 185 percent, respectively. Therefore, causing implementation of the policy, final price of cotton production will be increased from 7130 to 8190 Rials (complete removal of gasoline subsidies) and 13200 Rials (complete removal of electricity subsidies). Thus, it is recommended that removal of subsidies was done as gradually and warily program.

In order toinvestigation the effect of different amount of N-fertilizer and irrigation water on cotton yield of Varamin variety, an experiment was conducted in Kashmar agriculture and natural resource station in a Silty loam textured soil with EC=2.2 dS/m and pH=7.8. Experimental design was split plot as randomized complete block design with three replications which three levels of irrigation water including 45, 60 and 75 % cumulative evaporation of class A pan were as main plots and five levels of nitrogen including 0, 60, 120, 180 and 240 kg N/ha were as sub plots. Results showed that the effect of Nitrogen treatment on cotton yield, boll number, side branch number, and plant height was significant while N effect was not significant on boll weight. Irrigation treatments had significant effect on cotton yield. The highest cotton yield, boll number, side branch number, and plant height was obtained from 180 kg N/ha treatment and irrigation at 75 % evaporation from class A pan. By reducing of irrigation water, N-use efficiency decreased as well. In general results of this experiment showed that the best treatment was irrigation with 75 % evaporation from class A pan and 180 kg N/ha.

In order to evaluationthe best double cropping system in Golestan province,an experiment was carried out in 2010 in Karkandeh region (Kord kuy) in a split plot design based on RCBD with two factors and four replications. Main plotswere winter crop (wheat, pea, canola, bean and fallow)and subplots were twocottoncultivars(GolestanandSepid).Some agronomical, linter quality and cotton disease measured in this study. Analysis of variance indicated that,winter crop and cotton cultivarshadsignificanteffect on bolls number, bolls weight,earliness, total yield and linter quality. The effects winter crop significant differenceson thedisease dampingand verticillium. The most plant disease damping off percentin pea(%16.37) and decreasingin wheat (% 6.25) wereshowed.The most plant disease verticillium percentin fallow (%13.45) and decreasing in wheat (% 5.75) wereshowed.

Cotton plant is invaded by several sucking insect such as thrips ,aphid ,whitefly ,bugs and leaf hopper in northern part of Iran ,Golestan province. As introduction of in proved cotton cultivar with higher yield is the main object of cotton research institute,so it is important to screen the supreme lines with suitable tolerance to sucking insect. This study was carried out in cotton research station of Hashemabad (Gorgan) in during 2007and 2008 as complete randomized block design (CRBD) with 17 treatments and 4 replicationsin plots without pesticide spraying by 110 ×30 meters areas. Samplings was done weekly on 10 plants which were selected randomly and in each plant 3 leaves from top ,middle and bottom were inspected for counting and reading of important sucking insects including thrips,aphid and whiteflyand leaf hopper) was counted and rerecorded. The data was analysis by Excel. Bases on mean comparison of infestation rate of new cotton lines to sucking pests and also regarding to yield and earliness percent, tolerant lines includedTtabladila×Sahel-180,N200×Gukorova-80, Tabladila×Sahel-60,Siokra×Tabladila-133, Tabladila×Sahel-174,Siokroa×Tabladila-134were selected and future breeding programwill be done in view.

Cotton boll rot disease has observed in all the lands of world whichamount of damagesis different depending on the climate condition and it is more in humid areas. In this study, 20 different genotypes of cotton imported from Tajikistan were evaluated to identify and determine the amount of boll rotdisease. Experimentaldesign was based on randomized complete block with 4 replications. Results showed that S-65 ASR with 11.63% was the most sensitive genotypes to boll rot disease. The others genotypes had the least boll rot (B classe). The C148-TSHL ASR with 2.24%, TSHL ASR with 2.18%, SIO with 0.77%, NAMANGAN-77 with 1.16 %, F-108-1 with 0.83 %, N-13 with 1.5%, AK ASR with 1.12 %, HYSOZ with 0.25%, F-108 with0.68%, B-201-TSHL ASR with 0.76%, TAKHI-4 with 1.66%, J-74-6 with 3.24 %, KIRGIZY-3 with 0.76 %, H-220 ASR with 1.82%, F-108-6 with 1.46%, TSKHI-7 with 1.01%, SOGD-3 ASR with 0.59%, N-13 with 2.78%and Sahel with 0.81%had the least boll rot disease and were tolerance to boll rot disease.

Cotton (Gossipum hirsutumL.) is one of the most important agricultural and industrial crops in the world and Iran. Seed in agricultural crops including cotton, is the most important production input and cotton seed delinting is the most important processing step which is done by thermal, chemical and mechanical methods. In order to evaluation effect of three sulfuric acid concentrations including30, 40 and 50% and three temperatures of 40, 60 and 80oc,an experiment was conducted by standard germination test on seed germinability and vigor of Sahel and Varamin cultivars. Traits of investigation were included required time for delinting, seed final germination percentage, length, wet and dry weight of stem and radicle. The results was showed that using of diluted sulfuric acid by 30% concentration and temperature between 40-60 (depend on cultivar) was the optimum method for delinting, so that in Sahel and Varamin, optimum temperature was 40 and 60oc at the time of 90 and 30 minute, respectively. Also, Varamin cultivar was tolerant to high temperature in delinting than Sahel.